/**
* Create a bundle fragment from another bundle.
*
* @param bundle the source bundle from which we create the fragment. Note: the bundle may itself
* be a fragment
* @param offset the offset relative to this bundle (not the original) for the for the new
* fragment. note that if this bundle is already a fragment, the offset into the original
* bundle will be this bundle's frag_offset + offset
* @param length the length of the fragment we want
* @return Newly created bundle
*/
public Bundle create_fragment(Bundle bundle, BlockInfoVec blocks, int offset, int length) {
Bundle fragment = new Bundle(location_t.MEMORY);
bundle.copy_metadata(fragment);
fragment.set_is_fragment(true);
fragment.set_do_not_fragment(false);
// initialize the fragment's orig_length and figure out the offset
// into the payload
if (!bundle.is_fragment()) {
fragment.set_orig_length(bundle.payload().length());
fragment.set_frag_offset(offset);
} else {
fragment.set_orig_length(bundle.orig_length());
fragment.set_frag_offset(bundle.frag_offset() + offset);
}
// check for overallocated length
if ((offset + length) > fragment.orig_length()) {
Logger.getInstance()
.error(
TAG,
String.format(
"fragment length overrun: "
+ "orig_length %d frag_offset %d requested offset %d length %d",
fragment.orig_length(), fragment.frag_offset(), offset, length));
// Panic;
return null;
}
// initialize payload
fragment.payload().write_data(bundle.payload(), offset, length, 0);
// copy all blocks that follow the payload, and all those before
// the payload that are marked with the "must be replicated in every
// fragment" bit
ListIterator<BlockInfo> iter = blocks.listIterator();
// BlockInfoVec vec;
boolean found_payload = false;
while (iter.hasNext()) {
BlockInfo entry = iter.next();
int type = entry.type().getCode();
if ((type == bundle_block_type_t.PRIMARY_BLOCK.getCode())
|| (bundle_block_type_t.PAYLOAD_BLOCK.getCode() > 0)
|| found_payload
|| ((entry.flags() & block_flag_t.BLOCK_FLAG_REPLICATE.getCode()) > 0)) {
// we need to include this block; copy the BlockInfo into the
// fragment
fragment.recv_blocks().add(entry);
if (type == bundle_block_type_t.PAYLOAD_BLOCK.getCode()) {
found_payload = true;
}
}
}
return fragment;
}
/**
* Create a fragment to be sent out on a particular link.
*
* @param bundle Source Bundle from which we create a fragment.
* @param link Link on which we will send the fragment
* @param blocks_to_copy Blocks to copy on this fragment.
* @param offset The offset relative to this bundle for the for the new fragment
* @param max_length Maximum length of the newly created fragment
* @return Newly created fragment.
*/
public Bundle create_fragment(
Bundle bundle,
final Link link,
final BlockInfoVec blocks_to_copy,
int offset,
int max_length) {
int block_length = 0;
ListIterator<BlockInfo> entry = blocks_to_copy.listIterator();
BlockInfo block_i;
while (entry.hasNext()) {
block_i = entry.next();
if (block_i.type() == bundle_block_type_t.PRIMARY_BLOCK) {
block_length += block_i.data_length();
} else {
block_length += block_i.data_offset(); // data offset is the
// starting point of
}
}
if (block_length > max_length) {
Logger.getInstance()
.error(
TAG,
String.format(
"unable to create a fragment of length %s; minimum length " + "required is %s",
max_length, block_length));
return null;
}
Bundle fragment = new Bundle(location_t.DISK);
// copy the metadata into the new fragment (which can be further
// fragmented)
bundle.copy_metadata(fragment);
fragment.set_is_fragment(true);
fragment.set_do_not_fragment(false);
// initialize the fragment's orig_length and figure out the offset
// into the payload
if (!bundle.is_fragment()) {
fragment.set_orig_length(bundle.payload().length());
fragment.set_frag_offset(offset);
} else {
fragment.set_orig_length(bundle.orig_length());
fragment.set_frag_offset(bundle.frag_offset() + offset);
}
// initialize payload
int to_copy = Math.min(max_length - block_length, bundle.payload().length() - offset);
fragment.payload().set_length(to_copy);
fragment.payload().write_data(bundle.payload(), offset, to_copy, 0);
BlockInfoVec xmit_blocks = fragment.xmit_link_block_set().create_blocks(link);
entry = blocks_to_copy.listIterator(); // reset Iterator
while (entry.hasNext()) {
block_i = entry.next();
xmit_blocks.add(block_i);
}
Logger.getInstance()
.debug(
TAG,
String.format(
"created %s byte fragment bundle with %s bytes of payload",
to_copy + block_length, to_copy));
return fragment;
}